C.2. SPD Commands

Type the following commands (minimum match applies) in response to the prompt:
SPD>

SPD has a standard command line editing and prior command recall facility.

SPD> mode

Defines the mode in which the select command operates in selecting products to
display.

SPD> mode v

selection by variable or product number.

SPD> mode b

selection by baseline and/or polarisation.

SPD> mode

show current mode setting.

SPD> select

Selects which products to display.

1. Selection by product number ( mode v ):

In the following examples, the letters refer to the type of display. viz.

l - The lag spectrum, i.e. correlation function.

a - The amplitude of the frequency spectrum.

r - The real part of the frequency spectrum.

i - The imaginary part of the frequency spectrum.

p - The phase of the frequency spectrum.

d - The amplitude difference of the frequency spectrum, using a previously stored reference.

q - The amplitude quotient of the frequency spectrum, using a previously stored reference.

The numbers refer to the product numbers in the order they appear in the correlator/spectrometer configuration.
If only numbers are used, then the display type is set to the global display type (see below).

displays frequency spectra in two panels, each containing two products.

SPD> select a2-1

displays the difference frequency spectrum between two products.

SPD> select 1-2 4+5

displays difference and sum frequency spectra in two panels.

Special Parkes Multibeam Selection:

SPD> select mbN

displays lag or frequency spectra of N beams, two polarisations per plot panel, in the special Parkes multibeam layout.

2. Selection by frequency band/baseline/polarisation ( mode b ):

A new plot panel is created for each baseline and frequency band selected.

Examples:

Baseline, polarisation, frequency selection:

SPD> select 1aa

displays all baselines with antenna 1, polarisation AA, frequency 1.

SPD> select 12ba

displays baseline 1*2, polarisation BA, frequency 1.

SPD> select 14cc

displays baseline 1*4, polarisation AA, frequency 2.

SPD> select cd

displays all baselines, polarisation AB, frequency 2.

SPD> select 24

displays baseline 2*4, all polarisations.

SPD> select *

displays all active products

Frequency only selection, displaying all previously selected baselines/polarisations for the selected frequencies:

SPD> select f2

display frequency 2 only.

SPD> select f1 f3

display frequencies 1 and 3 only.

SPD> select f1-4

display frequencies 1 to 4 only.

SPD> select f*

display all frequencies.

SPD> select z1

display CABB zoom band 1 only.

SPD> select z1 z3

display CABB zoom bands 1 and 3 only.

SPD> select z1-2

display CABB zoom bands 1 to 2 only.

SPD> select z*

display all CABB zoom bands.

Note: The polarisation types must be enabled with the ON/OFF command
(see below). Initially only AA, BB, CC and DD are enabled. The use of C and D to
denote the A & B polarisations of the second frequency is allowed only for certain
two frequency operating modes. It is not allowed in cases where more than two
frequencies may be available, for example with MOPS and CABB. In these cases
control of which frequencies are displayed is via the fn parameter of
the ON/OFF command.

Then use one of the global display type commands (see below) to select the
display type.

SPD> select bp11

displays the time bin profiles for baseline 1*1, all polarisations.

SPD> select pp11

equivalent to above.

SPD> select dp

displays the de-dispersed pulsar bin profiles for all baselines and polarisations.

The bin profile plots the integral over frequency of the amplitude spectrum
against bin number. The limits of the integral (by default the entire spectrum)
can be defined by the bchannels command. bchannels also defines
the frequency range over which the de-dispersion is carried out.

SPD> select bi

displays the time bin image for all polarisations.

SPD> select biaa

displays the time bin image for polarisation AA.

The bin image shows colour coded amplitude difference as a function of bin number
on the X-axis and frequency channel on the Y-axis. The amplitude difference is
obtained by subtracting the band shape, computed from an average of the spectra of
all bins included in the plot, from the spectrum of each bin. X-axis limits are
set by the bpbins command. Y-axis limits are set by the bchannels command.

SPD> l or SPD> a or SPD> p or SPD> d or SPD> r or SPD> i

Sets the global display type and changes all current panels to this display type.

In baseline mode, and when time or pulsar binning is active, defines the currently
selected time bins.

Examples:

SPD> bins 1-5 10-16

selects bins 1 to 5 for frequency one, 10 to 16 for frequency 2.

SPD> bins 1.3.5 10.11

selects bins 1,3 & 5 for frequency one, 10 & 11 for frequency 2.

SPD> bins

show the currently selected bins.

SPD> on OR SPD> off

In baseline mode, defines which frequencies and polarisations are displayed, and
whether auto-correlations and/or cross-correlations are displayed.

Examples:

SPD> on ab ba cd dc

turn on display of all cross polarisation products.

SPD> off cc cd dc dd

turn off all second frequency polarisation products.

SPD> on f1 f4

turn on display of frequencies 1 and 4.

SPD> on ccs

turn on cross-correlations.

SPD> off acs

turn off auto-correlations.

SPD> on

display which types are currently displayed.

Note: The on or off commands for frequencies are probably
more conveniently carried out with the 'select fN' command (see above).

SPD> scale

Allows the plots to be scaled on the Y axis. The default is auto-scaling.

Examples:

SPD> scale l -0.01 0.01

scale lag plots to cover the range -0.01 to 0.01

SPD> scale b 0 200

scale bin profile plots to cover the range 0 to 200

SPD> scale a

return to auto-scaling for amplitude plots.

SPD> scale

autoscale all plots.

SPD> freq

For frequency domain plots, allows a selection of a range of frequencies to plot. The default is the full frequency range of the spectrum.

Examples:

SPD> freq [f1] 1146 2125

display the frequency range 1146 MHz to 2125 MHz for band 1.

SPD> freq f2 1146 2126

ditto for frequency band 2.

SPD> freq

reset to full band for all frequency bands.

SPD> freq f3

reset to full band for frequency band 3.

SPD> freq z2 1410 1420

set frequency range to plot for CABB zoom band 2.

SPD> channels

Allows a selection of a range of frequency channels to plot. The default is all
channels.

Examples:

SPD> channels [f1] 100 200

display channel range 100 to 200 for frequency band 1.

SPD> channels f2 200 500

display channel range 200 to 500 for frequency band 2.

SPD> channels 100 200 300 500

display channel range 100 to 200 for frequency band 1 AND channel range 300 to 500 for frequency band 2.

SPD> channels

reset channel selections to defaults.

SPD> bchannels

Allows the selection of a range of frequency channels to be used to compute the
bin or pulsar profile. The default is the range of channels defined by the
'channels' command. The format is the same as the 'channels' command.

SPD> lags

Allows a selection of a range of lag channels to plot. The default is all channels.

Examples:

SPD> lags [f1] -800 100

display lag channel range -800 to 100 for frequency band 1.

SPD> lags f2 -100 500

display lag channel range -100 to 500 for frequency band 2.

SPD> lags -200 200 -100 100

display lag channel range -200 to 200 for frequency band 1 AND lag channel range -100 to 100 for frequency band 2

SPD> lags

reset lag channel selections to default.

SPD> bpbins OR SPD> ppbins

In baseline mode, and when time or pulsar binning is active, defines the range
of bins over which bin profiles and bin images are plotted.

Examples:

SPD> bpbins 20 30

displays the bin profile for bins 20 to 30.

SPD> ppbins

reset to the full range of available bins.

SPD> avg

When the next data arrives, resets the averaging buffers and starts a vector
averaging in time of the frequency spectra. This also results in a time
averaging of bin profile and bin image displays.

SPD> noavg

When the next data arrives, reverts to non-averaging mode.

SPD> save

Saves the current frequency spectra amplitudes in a stored reference area.

SPD> rsave

Repetitively saves the previous frequency spectra amplitudes in a stored
reference area. This provides a means to continuously monitor changes, using
for example the difference display. Mainly useful for debugging problems, or
looking at how RFI is changing with time.

SPD> auto

When the next data arrives, resets the averaging buffers and enables an
automatic averaging mode where the averaging is reset at the start of each scan.
If the selected display is frequency spectrum amplitude and a scan is on a
reference position then the averaged data will be saved in the reference area
and subsequent signal scans will be displayed as quotient spectra.

SPD> noauto

Disable automatic averaging mode.

SPD> layout

Controls the layout of plot panels. The default layout is the smallest square
(NxN) layout which will contain the number of plot panels (with the exception
that a two panel layout defaults to 1x2) representing :
(number of panels in X) x (number of panels in Y). The maximum number of panels
is currently set to 16.

Examples:

SPD> layout 3x4

3 panels in X by 4 panels in Y.

SPD> layout [0x0]

revert to default layout.

SPD> write [[no]c[olour]] [filename]

Writes a colour (the default) or nocolour=greyscale postscript file of the
current display to the filename (if given), otherwise to a constructed filename
which includes date and time. The path used is the environment variable
$SPD_HARDCOPY (if defined), otherwise the directory from which SPD was
started. A message is printed identifying the actual filename used.

SPD> ss

Set SPD into "single shot" mode. The automatic update of the display is
disabled. Entering a further ss command causes the display to be updated. This
command is particularly useful when using SPD over slow links, to reduce
data flow.